A leading Christian campaigner yesterday called for a change in UK equality laws to include 'reasonable accommodation' in order to avoid a repeat of Northern Ireland's contentious same-sex cake case.

Simon Calvert is deputy director of public affairs at the Christian Institute, which has supported Ashers Baking Company during its prolonged legal battle.

He was speaking at a conference on free speech in London - just after the Belfast Telegraph revealed that Northern Ireland's Attorney General John Larkin QC was seeking to have the case heard at the Supreme Court.

Mr Calvert said that the McArthur family, who run and own the Co Antrim firm deemed to have breached equality laws by refusing to make a cake for a gay activist Gareth Lee bearing the slogan 'support gay marriage', should not have been obliged to fulfil his order.

"The reason they didn't want to provide the particular service, which was at a cost to them financially, was because of deeply-held, widely-shared, long-standing, mainstream Christian beliefs," he said. "My contention is that the law could have better accommodated them, but instead it punished them, so equality law must be changed.

"The law was not handed down from Heaven on tablets of stone. It was written by civil servants and politicians and campaigners and people make mistakes. That is why the law can be amended."

He added: "Equality law is just another law and if it's causing injustice and misery, if it's taking away freedom of speech and freedom of religion and freedom of conscience, then it should be changed."

'The Cake Wars: When Equality and Freedom Clash' debate was held at Conway Hall, Holborn, where Mr Calvert took part in a lively debate alongside Joshua Rosenberg, the UK's best-known legal commentator, and gay rights campaigner Peter Tatchell.

Mr Calvert said the only solution was to have "reasonable accommodation" written into equality law "in the tiny minority of cases where there is a clash of rights" so that the court would then be obliged to consider both sides.

He added: "In cases like Ashers, it might result in a fairer and arguably more humane outcome than what we got in Belfast."

Mr Tatchell, meanwhile, told the audience that he had initially described the Ashers verdict as a victory of equality, but had later changed his mind and now believes the judgment was wrong.

"In a democratic society people should be able to discriminate against ideas which they disagree with. The judgment has opened a can of worms," he said.

A spokesperson for Mr Larkin, meanwhile, said that in seeking to further appeal the case, the Attorney General had identified "a number of devolution issues".

The Court of Appeal is also expected to be asked on Tuesday to decide on the matter of the costs in the case, which are estimated at about £180,000.

As the McArthurs lost the case, they could be made liable for all legal costs.